Lattice for supporting a bunch of bar-shaped members

ABSTRACT

Grid for the support of primarily nuclear fuel bars, preferably a grid fashioned of the egg-crate type, in which fastening lips attached to the short connecting partitions pass through ample round holes in the long straps of the grid.

ilted States Patent [191 1 1 3,924,380 Quaadvliet I Dec. 9, 1975 LATTICE FOR SUPPORTING A BUNCH OF 3,156,957 11/1964 Moeckel 52/667 BAR-SHAPED MEMBERS FOREIGN PATENTS OR APPLICATIONS [75] Inventor: Hendricus Johannes Adrianus Q d li t Groet N h l d 1,141,432 12/1962 Germany 7. 52/664 [73] Assignee: Stichting Reactor Centrum Nederland, The Hague, Netherlands Primary ExaminerJohn E. Murtagh Assistant Examiner-Carl D. Friedman [22] Flled' June 1973 Attorney, Agent, or FirmCushman, Darby and [21] Appl. No.: 367,408 Cushman [30] Foreign Application Priority Data June 12, 1972 Netherlands 7207937 [57] ABSTRACT [52] CL 52/664 52/667 Grid for the support of primarily nuclear fuel bars, [51] Int. Cl E6 2/44 preferably a g fashioned of the egg crate yp in [58] Field S E a "52664468 which fastening lips attached to the short connecting partitions pass through ample round holes in the long [56] References Cited Straps of the UNITED STATES PATENTS 6 Claims, 20 Drawing Figures 1,749,902 3/1930 Bunker 52/667 X /12 l Bah H 28 J 1 J .1

US. Patent Dec. 9 1975 Sheet 2 of3 3,924,380

US. Patent Dec. 9 1975 Sheet 3 of3 3,924,380

LATTICE FOR SUPPORTING A BUNCH OF BAR-SHAPED MEMBERS The invention relates to a prior-art lattice which is especially serviceable for supporting a bunch of elongated members taking part in a process of heat exchange, which lattice is composed of parallel, equidistant, straight straps or strips, the side faces of which straps are likewise arranged in mutually parallel fashion, meshes being formed by connecting the straps at regular intervals by means of partitions positioned transversely to the strap direction. Such a lattice has so far been marked by the disadvantage that these straps and partitions were connected to each other by means of deep cuts in the straps. These cuts weakened the straps, especially because the bending strength was extensively affected. According to the invention, a partition is furnished on at least one side which rests against a strap with fastening lips that are passed through apertures in the wall. As a result, each strap remains stronger, because the apertures only constitute a minor interruption in the strap width and at any rate do not proceed continuously to the edge of the strap. The attachment becomes specifically highly simple from the point of view of manufacturing if these lips are fastened to the wall of another partition located on the other side of the aforementioned strap, in line with the first partition.

According to a variant, the measure can be taken that a lip is punched out of an aperture in the strap, which lip is fastened to the wall of a partition. This contributes to imparting additional strength of the lattice. According to another variant, a partition is furthermore furnished with one or more bent lips that are attached to a wall by the side of the partition.

The aperture made in the strap for passing the lips are preferably round. Care is also taken for these apertures to have a larger dimension than the width of a fastening lip to be passed through them. This measure allows the different strips to be mounted at different distances from each other. Differences in thickness occurring as a result of the pickling operation can thus be prevented from having any harmful effect upon the pitch of the lattice cells.

The successive connecting pieces must be positioned in exactly the same plane. The lips of those connecting pieces extending to other connecting pieces are therefore staggered over a distance corresponding to the thickness of the connecting piece. Staggering" is here understood to indicate a method according to which a lip is displaced parallel to itself over a given distance, in such a way that the transition from lip to plate exhibits two oppositely directed curvatures which are separated by a bending point.

The lips in successive lattice meshes should alternately be oppositely directed; if this measure is not taken, the lattice would eventually become deformed, assuming the form of a parallelogram.

Although the invention relates substantially to lattices composed of parallel straps with intermediate connecting pieces, it is also possible according to the invention to construct a lattice exclusively from strips. This design can sometimes prevent advantages where lattices must be provided in spaces having particularly erratic forms.

When a lattice of the kind as described hereinbefore is to provide support for elongated members such as fissile material bars, use is generally made of a spring fixation thereof. According to a prior-art method, rigid supporting lips are punched out of one wall in each lattice cell, a spring being provided on the opposite cell wall. Use is here preferably made of the springs specified in Netherlands Patent Applications Nos. 67-16920 and -l6,855.

The lattices are manufactured by mounting the connecting pieces, also called strips, around prismatic rods which are very exactly dimensioned and have recesses in the places where lips are present, whereupon the lips are fastened by spot welding. It is conducive to rapid processing and accurate work if the prismatic rods are grouped together to form an assembly fixture (also called a jig) which also bears spot-weld contact points.

The invention will be further explained on the basis of the following figures, which are merely intended as examples of embodiment. In these figures,

FIG. 1: represents a partition with lips that are opened out and lips that are not opened out.

FIG. 2: is a side view of the partition according to FIG. 1.

FIG. 3: is a top view of the partition according to FIG. 1.

FIG. 4: represents a strap with apertures provided therein.

FIG. 5: represents a variant of a partition.

FIG. 6: is a front view of the partition according to FIG. 5.

FIG. 7: is a top view of the partition according to FIG. 5.

FIG. 8: is a top view of a lattice according to the invention.

FIG. 9: is a top view of a portion of the lattice comprising a support according to the invention.

FIG. 10: is a variant of FIG. 9.

FIG. 11: is another variant of FIG. 9.

FIG. 12: is a variant ofa'partition drawn on a smaller scale.

FIG. 13: is another variant of a partition drawn on a smaller scale.

FIG. 14: is a variant of FIG. 4 with lips for spacers.

FIG. 15: is a top view of another spacer.

FIG. 16: is a side view of the spacer according to FIG. 15.

FIGS. 17 and 18: are across section and a top view, respectively, of a welding cap.

FIGS. 19 and 20: are a top view and a side view, respectively, of a rigid clip support functioning as a spacer.

FIGS. 1, 2 and 3 show different views of a connecting piece or strip 11 which bears 'rectangularly bent lips 14 and 15 as well as lips 12 and l3 which extend almost continuously. FIG. 3 clearly indicates that these lips 12 and 13 are slightly displaced parallel to themselves, i.e., they are staggered with respect to the body of the plate FIG. 4 is a view of a strap 20 with apertures 21 and 22 provided therein. The three views of FIGS. 5, 6 and 7 illustrate a variant of a partition as used on the side of the lattice where the last row of partitions are connected by their lips 24 to the strap 20 and those plates which form the corner of the lattice. The plate 23 here bears bent lips 24 and 25 as well as very short lips 26 which are not bent but remain in the plane of the plate portion of the strip 23.

FIG. 8 illustrates in a top view how a lattice 27 can be constructed from straps 20 and strips 11. This figure clearly indicates that all through this lattice there occur attachments of the type 28 and 29, i.e., the places of attachment are always constituted merely by two lips which are fastened to each other with a spot weld. Nowhere in the lattice is it necessary to fasten three lips to each other. This ensures uniformity in providing the spot welds, which can thus be of identical strength throughout the lattice. In FIG. 9, the number 32 indicates a U-shaped bent strip which serves as a fixed support for a fissile material-bar 33. In Flg. 16, a side view of such a fixed support isillustrated, while FIg. shows a top view thereof. These spacers can be mounted with the flat portion 34 against the straps from whichthe lattice are constructed. The attachment is likewise accomplished with the aid of a spot weld. The ends 35 abut against the side walls of the lattice cell which are composed of strips. As soon as pressure is applied by the spring 36to the fissile material bar 33, the latter will find a fixed support at the points 38 be cause the ends 35 cannot be displaced. FIG. 10 illustrates a fissile material bar 39 under the load of springs 36, the fixed supports being constituted by lips 41 that are punched and bent out of the straps 20, as shown in FIG. 14. 1 i

FIG. 11 illustrates'anembodiment where the fissile material bar 43 on the side opposite the springs 36 receives the fixed support of clips 44 which are fastened with a spot'weld to a lattice wall. FIGS. 19 and show a top view and a side view, respectively, of these clips.

FIG. 12 indicates another possible manner of punching fixed lip supports in the form of lips 30 from the strips themselves. FIG. 13 shows another variant, where two pairs of lips, 30 and 31, respectively, have been punched out and can be bent over. FIG. 14 represents a side view of a strap which is again provided with apertures 21 and 22 as well as with lips 41 which are punched out and bent so as to serve as fixed supports for the fissile material bars 39 of FIG. 10. FIG. 14 shows that these straps are furnished at the ends with lips 42 that are bent for being attached to the strips which are located entirely on the outside edge of the lattice.

FlGS.'l7 and 18 are a cross section and a top view, respectively, of a welding cap 45 as used for providing a spot weld between two walls 46 and 47which are made of such a material that it is not very practicable to join these walls directly to each other. In such case, use is made of a welding cap 45 designed as a small dish the recessed portion 48 of which extends throughthe aper ture 51 made in the wall 46 which consists ofa material that is hard to weld. The material of the cap 45 is of such a nature as to be highly weldable to the wall 47.

Application of the electrodes 49 and 50 produces a welded joint between the bottom 48 of the welding cap and the wall 47, so that the projecting edge or flange 52 of the welding cap presses the wall 46 against the wall 47. FIG. 17 shows the recessed design. Another possibility consists in having the edge 52 pressing directly on the outer surface of 46. FIG. 6 illustrates how welding apertures 51 can be arranged in a partition 23.

I claimr 1. A lattice for supporting a plurality of elongated members taking part in a process of heat exchange, such as nuclear'fissile fuel rods, said lattice comprising a plurality of partitions, each of said partitions having a spaced lip portion extending therefrom in the general plane of said strap, and a spaced tab portion disposed in a plane generally perpendicular to said lip portion, a plurality of partitions being disposed in generally the same plane in each of a plurality of columns forming the lattice, plurality of straps disposed in planes generally perpendicular to the planes of said partitions whereby "each strap forms a row of the lattice, each of said straps having a plurality of apertures formed therein receiving said lip portions of said partitions, said partitions being disposed so that a lip portion of one partition passes through the aperture of a strap and is attachedto a side face of the next consecutive partition so that'the partitions in each column are dipsosed in generally the same plane, and a tab portion of the one partition abuts-a face of the strap through which'a lip portion of the one partition is passed.

A lattice as recited in claim 1 wherein each of the apertures formedin'each of the straps is of larger dimension than the width of the partition lip portion which is passed therethrough.

' '3. A lattice as recited in claim 2 wherein each of said apertures are round, whereby impairment of sthe structural integrity of the straps is minimized.

' 4. A lattice as recited in claim 1 wherein consecutive partition lip portions are'attached to alternate partition side faces, and consecutive tab portions are dispoosed on al'ternatesides of corresponding apertures in con- 'secutive straps.

5. A lattice as recited in claim 1 wherein each of the connections between lip portions and partition side faces, 'and'tab portions and straps is formed by a spot weld.

6. A lattice as recited in claim 1 wherein each partition has a plurality of spaced lip and tab portions, and each strap has a plurality of apertures corresponding to said lip portions. 

1. A lattice for supporting a plurality of elongated members taking part in a process of heat exchange, such as nuclear fissile fuel rods, said lattice comprising a plurality of partitions, each of said partitions having a spaced lip portion extending therefrom in the general plane of said strap, and a spaced tab portion disposed in a plane generally perpendicular to said lip portion, a plurality of partitions being disposed in generally the same plane in each of a plurality of columns forming the lattice, a plurality of straps disposed in planes generally perpendicular to the planes of said partitions whereby each strap forms a row of the lattice, each of said straps having a plurality of apertures formed therein receiving said lip portions of said partitions, said partitions being disposed so that a lip portion of one partition passes through the aperture of a strap and is attached to a side face of the next consecutive partition so that the partitions in each column are dipsosed in generally the same plane, and a tab portion of the one partition abuts a face of the strap through which a lip portion of the one partition is passed.
 2. A lattice as recited in claim 1 wherein each of the apertures formed in each of the straps is of larger dimension than the width of the partition lip portion which is passed therethrough.
 3. A lattice as recited in claim 2 wherein each of said apertures are round, whereby impairment of sthe stRuctural integrity of the straps is minimized.
 4. A lattice as recited in claim 1 wherein consecutive partition lip portions are attached to alternate partition side faces, and consecutive tab portions are dispoosed on alternate sides of corresponding apertures in consecutive straps.
 5. A lattice as recited in claim 1 wherein each of the connections between lip portions and partition side faces, and tab portions and straps is formed by a spot weld.
 6. A lattice as recited in claim 1 wherein each partition has a plurality of spaced lip and tab portions, and each strap has a plurality of apertures corresponding to said lip portions. 